1. Field of the Invention
The present invention relates to support structure of an electronic device, such as a hard disk drive, which includes a printed circuit board (PCB) and facilitates the dissipation of heat from an integrated circuit (IC) mounted to the PCB. More particularly, the present invention relates to a hard disk drive which facilitates the dissipation of heat from a hard disk controller (HDC) or a combo IC mounted to the PCB of the drive.
2. Description of Related Art
Hard disk drives (HDDs) are memory devices that can record and reproduce a large amount of data at high speeds. Accordingly, hard disk drives are widely used as auxiliary memory devices for computer systems. A HDD generally includes a printed circuit board, ICs in the form of chips mounted to the printed circuit board, a platter having a magnetic layer on which data is recorded, and various mechanical parts that are used to rotate the platter and record and/or reproduce data onto or from the platter. In operation, electric power supplied to the PCB operates the mechanical parts under the control of one or more of the ICs such as an HDC (hard disk controller) or a combo IC. Accordingly, the IC generates heat. The heat generated in the HDD must be dissipated to prevent the HDD from malfunctioning, to prolong the useful life of the various parts of the HDD, and to prevent data recorded on the magnetic layer of a platter from being lost.
FIG. 1 shows a base 160, a printed circuit board 110, and ICs 122 of a conventional HDD. In the conventional HDD, the base 160 and printed circuit board 110 are coupled to each other by screws 121. Also, the ICs 122 are installed on a surface of the PCB 110. Particular ones of the ICs 122 such as an HDC 126, a combo IC (not shown), and a memory chip 128 conduct a great amount of current and thus, generate a great deal of heat.
More specifically, the PCB 110 has a via hole 111, and a conductive pad connected to an inner circumferential wall 111a that forms the via hole 111. The inner circumferential wall 111a is formed by copper plating the substrate of the PCB in a through-hole of the substrate. A ground 122a coupled to the lower surface of the IC 122, such as the HDC 126, is connected to the conductive pad 111b by solder 119 at the upper surface of the PCB 110. The via hole 111 is located in an area of the PCB 110 above which the IC 122 is disposed. The heat generated by the IC 122 is dissipated by conduction via the ground 122a, solder 119, the conductive pad 111b, and inner circumferential wall 111a, and by convection at the inner circumferential wall 111a, as indicated by the arrows in the enlarged portion of FIG. 1.
However, in the conventional HDD, the heat generated by the IC 122 is also transferred along the PCB 110 in the directions indicated by the arrows on the PCB 110. The heat is transferred to the base 160 via the screws 121 and bosses 163 of the base 160 to which the screws 121 are threaded. The base 160 is formed of aluminum. The heat spreads over the entire surface of the PCB 110 as the heat is transferred to the base 160. Thus, the heat passes through surrounding devices 125 mounted to the PCB 110. The heat negatively affects the surrounding devices 125 or adds to the heat radiating from the respective ICs 122. As a result, the overall average temperature of the PCB 110 becomes excessive.
Additional heat dissipating structures have been considered to solve the above-described problem. However, such structures tend to be complex and therefore difficult to manufacture, the manufacturing of an additional heat dissipating structure adds to the cost of the HDD, and the addition of another heat dissipating structure could undesirably increase the bulk of the HDD.